TuesdayTool 28: Censys, An Excellent Digital Asset Search Engine

Introduction

Censys is a comprehensive internet intelligence platform designed to help cybersecurity professionals discover, monitor, and analyze devices accessible from the Internet (internet-facing assets). It provides a detailed overview of an organization’s attack surface by continuously scanning the entire Internet to identify potential vulnerabilities on Internet-facing assets and exposed assets not designed to be accessible from the Internet.

Censys is one of the most powerful OSINT tools used for threat intelligence, brand monitoring, and attack surface management. Censys can be used by the vulnerability management team, threat intelligence team, and the offensive security team for scanning.

Censys homepage

Key Features of Censys

• Internet-Wide Scanning: Censys uses techniques similar to ZMap, an open-source project developed by researchers at the University of Michigan, to scan the Internet and gather data on publicly reachable devices.
• Data Collection and Analysis: Censys collects and enriches data from these scans, making it accessible through an interactive search engine and API. This data includes information about services running on devices, TLS certificates, and domain names.
• Attack Surface Management: Censys helps organizations understand their internet-facing attack surface, provides visibility on vulnerabilities associated with their internet-facing assets, and takes steps to secure their networks

Teams that can use Censys:

1. Threat Intelligence teams.
2. Threat hunting teams.
3. Offensive security teams such as Penetration testers, and ethical hacking.
4. Vulnerability management team.

Accessing Censys Search

1. Visit Censys Search: Navigate to search.censys.io to start using the platform.
2. Create an Account: While it is not a requirement, creating a free account enhances your experience by providing access to more features and better support.

For this article, I will provide a comprehensive guide on how to utilize Censys for these purposes:

Threat Intelligence

Threat intelligence involves gathering, collecting, and analyzing data to understand potential threats to an organization’s security. Similarly, Censys provides actionable threat intelligence by offering a comprehensive view of the internet, which helps in identifying and mitigating threats.

Steps to Use Censys for Threat Intelligence:

1. Sign Up and Access Censys Search: Start by signing up for a Censys account and accessing the Censys Search tool. Censys allows users to query the internet for specific data, such as IP addresses, domains, or software versions.
2. Build Queries: Users can use Censys Search to build queries that help identify potential threats. This can include searching for specific malware indicators of compromise (IOCs), suspicious network activity, or unpatched vulnerabilities.
3. Analyze Results: Analyze the results from your queries to identify potential threats. Censys provides detailed information about hosts and services, which helps to understand the threat landscape.
4. Track Malware Infrastructure: Users also use Censys to track malware infrastructure by identifying command and control (C2) servers, malicious domains, or other IOCs related to malware campaigns.

Brand Monitoring

Brand monitoring protects the brand reputation of any organization. It involves tracking mentions of an organization’s brand across the internet to ensure that your brand’s assets are secure and not being misused or impersonated. Censys provides a feature for monitoring your brand’s digital footprint.

Steps to Use Censys for Brand Monitoring:

1. Identify Brand Assets: Start by identifying all your brand’s digital assets, including internet-facing IP addresses, domains, subdomains, and software used in and by your organization.
2. Use Censys Search: Use Censys Search to query these assets and monitor for any unauthorized use or exposure. This search can include searching for domains similar to your brand’s domain to detect potential phishing or impersonating sites.
3. Set Up Alerts: Users can also set up alerts within Censys to notify whenever new assets are discovered or changes are detected in their existing assets. This helps to proactively respond to potential brand misuse.
4. Analyze Results: Censys can assist users to regularly analyze the results from their queries to identify any potential risks to their brand’s reputation or security.

Attack Surface Management

Attack surface management involves identifying and managing all the potential initial points an attacker could use to gain unauthorized access to your network. Censys provides comprehensive tools for attack surface management.

Steps to Use Censys for Attack Surface Management:

1. Discover Assets: Use Censys Attack Surface Management (ASM) to discover all your organization’s internet-facing assets, including servers, devices, cloud services, and much more.
2. Identify Vulnerabilities: Censys ASM helps identify vulnerabilities in your assets by mapping Common Vulnerabilities and Exposures (CVEs) and Known Exploited Vulnerabilities (KEVs) with your organization’s assets.
3. Prioritize Risks: Use the Common Vulnerability Scoring System (CVSS) scores and KEV flags to prioritize vulnerabilities based on their severity and exploitability.
4. Remediate Vulnerabilities: Implement remediation strategies for identified vulnerabilities. Censys also provides tools to track and manage the remediation process.
5. Monitor Continuously: Continuously monitor your attack surface for new exposures and changes. Censys updates its data daily, ensuring you have the most current view of your attack surface.

Conclusion

One thing that stood out in all the use cases explained above is the ability to understand your organization’s threat domain, having an effective asset inventory practice will go a long way to using any tool effectively. By following these steps, organizations can effectively use Censys for threat intelligence, brand monitoring, and attack surface management to enhance their cybersecurity posture.

Till I come your way again next 2 weeks Tuesday, #BeCyberSmart

Cyberliza writes TuesdayTool